<?php  // $Id: authlib.php,v 1.8.2.6 2008/05/28 07:39:52 dongsheng Exp $
/**
 * @author Martin Dougiamas
 * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
 * @package moodle multiauth
 *
 * Multiple plugin authentication
 * Support library
 *
 * 2006-08-28  File created, AUTH return values defined.
 */

/**
 * Returned when the login was successful.
 */
define('AUTH_OK',	 0);

/**
 * Returned when the login was unsuccessful.
 */
define('AUTH_FAIL',   1);

/**
 * Returned when the login was denied (a reason for AUTH_FAIL).
 */
define('AUTH_DENIED', 2);

/**
 * Returned when some error occurred (a reason for AUTH_FAIL).
 */
define('AUTH_ERROR',  4);

/**
 * Authentication - error codes for user confirm
 */
define('AUTH_CONFIRM_FAIL', 0);
define('AUTH_CONFIRM_OK', 1);
define('AUTH_CONFIRM_ALREADY', 2);
define('AUTH_CONFIRM_ERROR', 3);

# MDL-14055
define('AUTH_REMOVEUSER_KEEP', 0);
define('AUTH_REMOVEUSER_SUSPEND', 1);
define('AUTH_REMOVEUSER_FULLDELETE', 2);

/**
 * Abstract authentication plugin.
 */
class auth_plugin_base {

	/**
	 * The configuration details for the plugin.
	 */
	var $config;

	/**
	 * Authentication plugin type - the same as db field.
	 */
	var $authtype;
	/*
	 * The fields we can lock and update from/to external authentication backends
	 */
	var $userfields = array(
		'firstname',
		'lastname',
		'email',
		'city',
		'country',
		'lang',
		'description',
		'url',
		'idnumber',
		'institution',
		'department',
		'phone1',
		'phone2',
		'address'
	);

	/**

	 * This is the primary method that is used by the authenticate_user_login()
	 * function in moodlelib.php. This method should return a boolean indicating
	 * whether or not the username and password authenticate successfully.
	 *
	 * Returns true if the username and password work and false if they are
	 * wrong or don't exist.
	 *
	 * @param string $username The username (with system magic quotes)
	 * @param string $password The password (with system magic quotes)
	 *
	 * @return bool Authentication success or failure.
	 */
	function user_login($username, $password) {
		error('Abstract user_login() method must be overriden.');
	}

	/**
	 * Returns true if this authentication plugin can change the users'
	 * password.
	 *
	 * @return bool
	 */
	function can_change_password() {
		//override if needed
		return false;
	}

	/**
	 * Returns the URL for changing the users' passwords, or empty if the default
	 * URL can be used. This method is used if can_change_password() returns true.
	 * This method is called only when user is logged in, it may use global $USER.
	 *
	 * @return string
	 */
	function change_password_url() {
		//override if needed
		return '';
	}

	/**
	 * Returns true if this authentication plugin is "internal" (which means that
	 * Moodle stores the users' passwords and other details in the local Moodle
	 * database).
	 *
	 * @return bool
	 */
	function is_internal() {
		//override if needed
		return true;
	}

	/**
	 * Updates the user's password. In previous versions of Moodle, the function
	 * auth_user_update_password accepted a username as the first parameter. The
	 * revised function expects a user object.
	 *
	 * @param  object  $user		User table object  (with system magic quotes)
	 * @param  string  $newpassword Plaintext password (with system magic quotes)
	 *
	 * @return bool				  True on success
	 */
	function user_update_password($user, $newpassword) {
		//override if needed
		return true;
	}

	/**
	 * Called when the user record is updated.
	 * Modifies user in external database. It takes olduser (before changes) and newuser (after changes)
	 * conpares information saved modified information to external db.
	 *
	 * @param mixed $olduser	 Userobject before modifications	(without system magic quotes)
	 * @param mixed $newuser	 Userobject new modified userobject (without system magic quotes)
	 * @return boolean true if updated or update ignored; false if error
	 *
	 */
	function user_update($olduser, $newuser) {
		//override if needed
		return true;
	}

	/**
	 * User delete requested - internal user record is mared as deleted already, username not present anymore.
	 * Do any action in external database.
	 * @param object $user	   Userobject before delete	(without system magic quotes)
	 */
	function user_delete($olduser) {
		//override if needed
		return;
	}

	/**
	 * Returns true if plugin allows resetting of internal password.
	 *
	 * @return bool
	 */
	function can_reset_password() {
		//override if needed
		return false;
	}

	/**
	 * Returns true if plugin allows resetting of internal password.
	 *
	 * @return bool
	 */
	function can_signup() {
		//override if needed
		return false;
	}

	/**
	 * Sign up a new user ready for confirmation.
	 * Password is passed in plaintext.
	 *
	 * @param object $user new user object (with system magic quotes)
	 * @param boolean $notify print notice with link and terminate
	 */
	function user_signup($user, $notify=true) {
		//override when can signup
		error('user_signup method must be overriden if signup enabled');
	}

	/**
	 * Returns true if plugin allows confirming of new users.
	 *
	 * @return bool
	 */
	function can_confirm() {
		//override if needed
		return false;
	}

	/**
	 * Confirm the new user as registered.
	 *
	 * @param string $username (with system magic quotes)
	 * @param string $confirmsecret (with system magic quotes)
	 */
	function user_confirm($username, $confirmsecret) {
		//override when can confirm
		error('user_confirm method must be overriden if confirm enabled');
	}

	/**
	 * Checks if user exists in external db
	 *
	 * @param string $username (with system magic quotes)
	 * @return bool
	 */
	function user_exists() {
		//override if needed
		return false;
	}

	/**
	 * return number of days to user password expires
	 *
	 * If userpassword does not expire it should return 0. If password is already expired
	 * it should return negative value.
	 *
	 * @param mixed $username username (with system magic quotes)
	 * @return integer
	 */
	function password_expire($username) {
		return 0;
	}
	/**
	 * Sync roles for this user - usually creator
	 *
	 * @param $user object user object (without system magic quotes)
	 */
	function sync_roles($user) {
		//override if needed
	}

	/**
	 * Read user information from external database and returns it as array().
	 * Function should return all information available. If you are saving
	 * this information to moodle user-table you should honor syncronization flags
	 *
	 * @param string $username username (with system magic quotes)
	 *
	 * @return mixed array with no magic quotes or false on error
	 */
	function get_userinfo($username) {
		//override if needed
		return array();
	}

	/**
	 * Prints a form for configuring this authentication plugin.
	 *
	 * This function is called from admin/auth.php, and outputs a full page with
	 * a form for configuring this plugin.
	 */
	function config_form($config, $err, $user_fields) {
		//override if needed
	}

	/**
	 * A chance to validate form data, and last chance to
	 * do stuff before it is inserted in config_plugin
	 * @param object object with submitted configuration settings (without system magic quotes)
	 * @param array $err array of error messages
	 */
	 function validate_form(&$form, &$err) {
		//override if needed
	}

	/**
	 * Processes and stores configuration data for this authentication plugin.
	 *
	 * @param object object with submitted configuration settings (without system magic quotes)
	 */
	function process_config($config) {
		//override if needed
		return true;
	}

	/**
	 * Hook for overriding behavior of login page.
	 * This method is called from login/index.php page for all enabled auth plugins.
	 */
	function loginpage_hook() {
		global $frm;  // can be used to override submitted login form
		global $user; // can be used to replace authenticate_user_login()

		//override if needed
	}

	/**
	 * Post authentication hook.
	 * This method is called from authenticate_user_login() for all enabled auth plugins.
	 *
	 * @param object $user user object, later used for $USER
	 * @param string $username (with system magic quotes)
	 * @param string $password plain text password (with system magic quotes)
	 */
	function user_authenticated_hook(&$user, $username, $password) {
		//override if needed
	}

	/**
	 * Pre logout hook.
	 * This method is called from require_logout() for all enabled auth plugins,
	 */
	function prelogout_hook() {
		global $USER; // use $USER->auth to find the plugin used for login

		//override if needed
	}

	/**
	 * Hook for overriding behavior of logout page.
	 * This method is called from login/logout.php page for all enabled auth plugins.
	 */
	function logoutpage_hook() {
		global $USER;	 // use $USER->auth to find the plugin used for login
		global $redirect; // can be used to override redirect after logout

		//override if needed
	}

	/**
	 * Return the properly translated human-friendly title of this auth plugin
	 */
	function get_title() {
		$authtitle = get_string("auth_{$this->authtype}title", "auth");
		if ($authtitle == "[[auth_{$this->authtype}title]]") {
			$authtitle = get_string("auth_{$this->authtype}title", "auth_{$this->authtype}");
		}
		return $authtitle;
	}

	/**
	 *  Get the auth description (from core or own auth lang files)
	 */
	function get_description() {
		$authdescription = get_string("auth_{$this->authtype}description", "auth");
		if ($authdescription == "[[auth_{$this->authtype}description]]") {
			$authdescription = get_string("auth_{$this->authtype}description", "auth_{$this->authtype}");
		}
		return $authdescription;
	}
	
	/**
	 * Returns whether or not the captcha element is enabled, and the admin settings fulfil its requirements.
	 * @abstract Implement in child classes
	 * @return bool
	 */
	function is_captcha_enabled() {
		return false;
	}


}

?>
